It was a big issue after WW2, my Mum was v worried because she considered me too 'skinny' - mainly because I was a picky eater and our diet was very bland and repetitive. Think, no vegs out of season and no veg from overseas, hardly any meat or fats available, even bread was rationed. The favourite vegs at meals was a mix of carrots and Swede (my husband still loves it)
So mothers would have flocked to buy Ovaltine and other high calorie additions for their children
Yes we possibly were on the cusp of starvation although most were more healthy than they'd ever been - thanks to rationing which gave us an adequate, if boring, diet.
I remember craving sweetness.